Solubility and diffusion coefficient of oxygen in silicon

The solubility and diffusion coefficient of oxygen in silicon between 10000C and 13750C were examined by charged particle activation analysis with the 16O(3He,p)18F reaction, in which oxygen was activated with an equal probability over the depth of up to 250μm by a specially devised apparatus. Silicon wafers of known histories were heated in oxygen or argon for 12 to 473 hours, and the resultant oxygen depth profiles were determined by the activation, subsequent stepwise etching and 18F activity measurement. The solubility thus obtained is given as 9.3 x 1021 exp[-27.6kcal mol-1/RT] at.cm-3; the diffusion coefficient has been found to be approximated as 3.2 exp[-67.1kcal mol-1/RT] cm2s-1 over 11500C, under which the apparent activation energy seems to decrease with decrease of temperature. (author)